1. Field of the Invention
The present invention relates to a semiconductor device which has aimed to improve heat dissipation efficiency and a method for manufacturing the same.
2. Description of the Related Art
In an IC package packing a semiconductor chip in the package, there is a case where a heat spreader is provided in order to efficiently dissipate heat from the semiconductor chip to the outside (for example, refer to Patent Document 1). A heat spreader is sometimes called a heat sink. Further, a heat spreader is sometimes used in a system-in-package (SIP) packing a plurality of semiconductor chips and peripheral circuit parts in a package.
In general, a heat spreader is bonded to the backside of a semiconductor chip. For the bonding, solder (PbSn) is used. Then, heat produced from the semiconductor chip is conducted to the heat spreader and the heat is dissipated to the outside by natural cooling or forced cooling.
Consequently, it is required for the thermal conductivity to be high from the semiconductor chip to the heat spreader because the heat from the semiconductor chip is dissipated at high efficiency. On the other hand, accompanying the recent advancement of the function of the semiconductor chip, the quantity of produced heat is increased. Because of this, a structure is demanded which is capable of realizing higher heat conductivity.
Related arts are disclosed in Patent Document 1 (Japanese Patent Application Laid-open No. 2006-108296), Patent Document 2 (Japanese Patent Application Laid-open No. Sho 52-61152), Patent Document 3 (Japanese Patent Application Laid-open No. Sho 63-228650), and Patent Document 4 (Japanese Patent Application Laid-open No. Sho 54-132774).